Research On Aero-engine Case Ring Pre-forming And Strengthening Mechanism Of GH4169

For Made in China 2025,the aero-engine project is extremely urgent.As an important part of the heart of the aircraft,the performance requirements of casing ring forgings should also follow the development trend.However,the stock utilization of casing ring forgings is less than 5%.Pre-forging by loose tooling forging can greatly increase the forming precision.So allowance needed will be decreased and stock utilization will be increased.But the tonnage requirement of equipment during loose tooling forging seriously restricts the product of casing ring forgings.In order to solve this problem,the pre-forming process of the GH4169 ring forgings was investigated was studied,and the pre-forming process is optimized.At the same time,through the study of the strengthening mechanism of superalloy GH4169 hot forming process,deepen the knowledge of deformation characteristics in the process of hot forming.In order to predict the macroscopic and microscopic changes during the process of hot forming better,the strengthening mechanism is necessary to grasped.According to the pre-forming ring blank,the forming molds and corresponding blank were designed,and a simulation model of the whole forming process was established on the Deform platform.The metal flow,filling and molding load variation rules during the whole forming process were analyzed.On this basis,the optimization scheme of rectangular section ring multiple forming and shaped section ring once forming was proposed.In order to improve the formulation efficiency of rectangular section ring multiple forming process,an empirical formula for estimating the times of forming to the tonnage of equipment is proposed.Combined with Deform platform,the process plan of r rectangular section ring multiple forming was simulated.In view of the shaped section ring once forming craft,the process optimization was carried out on the Deform platform in the same way,the final ring billet size was determined,and the loose tooling forging of pre-forming of casing on equipment of small tonnage was realized.At the same time,the metal filling rules of the two forming craft are analyzed.In order to deeply understand the strengthening mechanism inside the metal,the problem of forming load is understood theoretically.A strengthening model reflectingthe internal physical laws of hot forming process from the perspective of dislocation is constructed,and the strengthening mechanism of metal is explained by the strengthening model.The computational process of the strengthening model is realized through computer programming,and then the accuracy of the strengthening model is verified through experiments.On this basis,the physical state changes in the metal hot machining process are reflected by the physical quantity change rules of the strengthening model.Study shows that the improved model consistent with the experimental results on stress prediction,and the grain size changes,has made the forecast,dynamic recrystallization volume fraction are also reflects the changing rule of the internal density of dislocation density,can to a certain extent,reflects the strengthening mechanism of the stress is too small,but the stress contributed by grain size does not accord with existing theory,so the constitutive model remains to be further improved.The research on the preform of the casing ring forgings in this topic provides a solution to the problem of large forming load in actual production.The research on the strengthening mechanism,on the one hand,strengthens the understanding of deformation characteristics in the hot working process,and on the other hand,provides a reference and idea for the explanation of the strengthening mechanism in the hot working process of metals.